Join Brian Lee White for an in-depth discussion in this video Using compression to add punch and sustain to drums, part of Get in the Mix with Logic Pro.
Let's take a look at how to apply compression to a single note, using it to draw out the attack or sustain or a signal and letting that note punch through dense musical sections of the mix. This type of compression is often referred to as envelope shaping or transient shaping. A shape of a note's waveform is called its envelope. The envelope describes how a note evolves over time. Think of envelope as the trip of signal wave form it takes from initial development to final decay. Let's take a look at a snare drum note envelope. We start with a sharp transient, this is referred to as the attack.
This sharp transient is followed by a brief sustain and final release period as the sound dies out. Because a compressor reacts to a signal's amplitude as it changes over time, we can use compression to play with the shape of the signals envelope. Listen to this snare drum without any compression. Pay attention to the sound of the attack and release. Now, listen to the same scenario with compression applied, and listen for how the sound has changed. Notice how in the compressed version, the attack of the signal is pulled up and has more punch. This is achieved by adjusting the attack time of the compressor to allow a bit of the original transient through, before being compressed.
An attack time of between one and ten milliseconds works great for this, but any longer, and I risk missing the transient altogether. After making up the gain from the compression, what we end up with is a larger transient or initial attack portion of the sound than we started with because the body or sustain portion of the sound has been attenuated. Thus, changing the dynamic relationship between the two. A muted copy of the processed waveform has been provided as a visual reference underneath the active snare track. Now, listen again to the snare in the context of the full mix.
And pay attention as I automate the settings to apply the compression. I'm exaggerating a bit here, so you can really hear the compression. But notice how the punchier snare helps the drum kit drive the song. Dynamics are all about relative relationships in amplitude. In this case, I've changed the relationship between the attack and the rest of the snare hit. The more aggressive the threshold and ratio settings I use, the more distance I create between the transient and the rest of the snare hit. We can achieve the opposite effect by using fast release times.
Let's take a listen to very fast release time on the snare drum. Again, I've exaggerated the effect so you can really hear the change in the shape of the snare envelope. By allowing the compressor to compress the initial transient body of the snare drum, and quickly release the compression before the softer decay section, we can use the make up gain to inflate the tail of the signal and draw it out longer in time. Notice how I'm driving the compressor a little harder here, achieving more gain reduction. This trick works best with more aggressive threshold and ratio settings. Feel free to zoom in and look at the processed example track's wave form to better visualize what's happening.
You want to watch your attack when you reach these levels of gain reduction. Even a small amount of transient escaping through uncompressed can eat up all your headroom and clip the output. This trick doesn't work on every kind of material with every compressor, so use your judgement. Sometimes I split the track into two and process one for a sharper attack and another for more sustained and then blend the two to taste. Some compressors are better at each of these tasks than others. In order achieve effective envelope shaping with the compressor, we're generally looking for a processor with a very fast attack and release time.
A slower compressor, or one without attack and release controls, may not be fast enough to really draw out the envelope precisely.
This course covers 23 techniques for improving your mixes with compressors, processors, EQ and filters, delay, and modulation. The first chapter covers compression and dynamics processing, including how to even out vocal performances and add punch to drum tracks. The second chapter goes into EQ and filtering techniques, such as creating complimentary EQ curves and EQ-ing FX returns. Last, the authors explore delay and modulation techniques, including using long delay on key lyrics and creating flanger and phaser effects.
Download the free exercise files and open them in Logic to start training, or simply watch the videos here at lynda.com.
- Using compression to even out vocals and add punch to drums
- Maximizing mix loudness
- De-essing a vocal track
- Using EQ to fix problems and place elements
- Automating EQ
- Using long delay
- Creating slapback echo
- Creating a flange effect